Piggy is the most rational member on the island. He's intelligent, level headed, and thinks before he speaks. Jack and the other boys are threatened by his ability to vocalize his thoughts in a rational manner and his loyalty to Ralph. Thus, they demean him at every opportunity. Piggy's glasses also represent science and civilization. They make fire, which makes them an object of desire. His glasses also symbolize the ability to see clearly with clarity and understanding.
